1. Field of the Invention
The present invention relates to a wheel having rotating bodies in which a plurality of non-turning type rotating bodies to be rotated in a direction orthogonal to the straight-forward direction of the wheel are disposed around the wheel for changing the advancing direction.
2. Description of the Related Art
Regarding the wheel having the rotating bodies, the wheel in which roller-like rotating bodies to be rotated in the direction orthogonal to the straight-forward direction are disposed on a rotary shaft along an outer circumferential circle of the wheel, and a buffer member is disposed between the rotating bodies is disclosed in Japanese Unexamined Patent Application Publication No. 11-227404. In addition, the wheel having a large number of spindle-like rotating bodies disposed in an inclined manner to the straight-forward direction under the assumption that drive wheels are provided is disclosed in Japanese Examined Patent Application Publication No. 7-12829 or Japanese Patent Publication No. 10-500049 (by PCT Application).
By using the former wheel, the wheel can be traveled in the transverse direction or diagonally while the wheel is rotated according to the vector component by the rotating bodies for shifting course without any turn different from a caster, i.e., without increasing the width of the wheel; however, a space is essentially generated between forward and rear ends of the adjacent rotating bodies with the width corresponding to the diameter of the rotating bodies. Thus, the buffer member is interposed in the space since stones or the like are caught therein; however, there leaves a room for improvement in that a frictional resistance with the rotating bodies is generated, and the rotating bodies cannot be rotated smoothly by the non-rotation.
On the other hand, by using the latter wheel, the wheel can be similarly traveled in the transverse direction or diagonally without any turn by the diagonal rotating bodies for shifting course; however, a space is generated between the adjacent circumferential surfaces of the rotating bodies, and if the diameter of the wheel is increased and the width in the longitudinal direction of each rotating body in the straight-forward direction is suitably increased considering the ride-over of a step, the transverse width of the wheel, i.e., the radius of turn of the wheel is naturally increased by the rotating bodies in the diagonal arrangement.
Accordingly, it is an object of the present invention to provide a wheel having rotating bodies which is provided with non-turning type rotating bodies to suppress generation of a space between the rotating bodies.
In the present invention, each rotating body rotated in the direction orthogonal to the straight-forward direction of the wheel is rotatably supported around the axis of rotation across the radial direction around an axle, and each rotating body is formed in a shape that the diameter of a tip portion thereof is smaller than the diameter of a base end portion, and an arc of an outer circumferential circle of the wheel is formed by the circumferential surface. The rotating bodies are rotatably supported on the axis of rotation across the radial direction, and the diameter is gradually reduced from the base end portion to the tip portion, or once increased, and then reduced to form an outer circumferential circle of the wheel by the circumferential surface.
In accordance with the present invention, the turn in the advancing direction like a caster is unnecessary, the advancing direction of a vehicle can be freely changed diagonally or in the longitudinal direction, and the space between the rotating bodies can be small enough to prevent the interference of the space between the rotating bodies even when the diameter of the wheel is increased so that the step can be easily got over.
When the tip portion of each rotating body penetrates a recessed portion of the counter base end portion, the space between the rotating bodies can be further reduced. An outer circumferential portion of the base end portion formed as the recessed portion of each rotating body is formed as an annular lip which is elastic according to the material of the rotating body, and when an annular stepped portion to allow penetration of the lip of the adjacent rotating body is formed in the tip portion of each rotating body, degradation of the true circularity caused by the space between the rotating bodies, i.e., generation of rattling noises in the rotating mode is suppressed.
If each rotating body is of a half-spindle shape in which the diameter thereof is continuously reduced from the base end portion to the tip portion, the difference in diameter between the forward and rear ends is increased, and the rotating bodies are easily brought close to each other to reduce the space.
Each rotating body comprises a core portion rotatably supported around the axis of rotation and an outer cylindrical portion which surrounds the core portion around the axis of rotation and is a die casting formed of an elastic material, and if protruding and recessed portions which are engaged with each other in a shape-complementary manner by changing the section in the direction of the axis of rotation in protruding and recessed shape are formed on an outer circumferential surface of the core portion and an inner circumferential surface of the outer cylindrical portion, the wall thickness thereof can be limited when they are manufactured of die castings of a synthetic resin or rubber, and as a result, generation of small internal defects specific to the castings can be prevented, and generation of abnormal noises in the traveling mode can be suppressed. In this state, if the core portion and the outer cylindrical portion are formed of a synthetic resin such as a polyurethane, and engaging surfaces of the protruding and recessed portions are adhered to each other, an appropriate elasticity to suppress the vibration is realized to easily and reliably enable the engagement. When the core portion is formed of a metal, generation of small internal defects in the die casting of the outer cylindrical portion can be avoided.
When a bearing arm with the base end portion mounted on the rim penetrates into a space between the tip portion of the rotating body and the recessed portion of the adjacent rotating body, the rotating bodies adjacent to each other with a small space therebetween can be rotatably supported with an excellent appearance and a simple structure using the arm.